The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 28, 1987
Filed:
Mar. 28, 1986
Jan S Porowski, Pittsburgh, PA (US);
William J O'Donnell, Bethel Park, PA (US);
Manu L Badlani, Pittsburgh, PA (US);
Edward J Hampton, Murrysville, PA (US);
O'Donnell & Associates, Inc., Pittsburgh, PA (US);
Abstract
A process is claimed for removing the residual tensile welding stresses in the inner layer of the weld metal and the heat-affected zone of steel piping elements that have been butt-welded to each other end-to-end by means of a circumferential weld. The process involves mechanically introducing circumferential compressive stresses in the piping elements by applying a radial load inwardly on a section of at least one of the piping elements away from the weld such that the distance from the midplane of the section of the piping element upon which the radial load is applied to the weld midplane is equal to about two to about 12 times the thickness of the piping element upon which the radial load is applied. The distance from the edge of the section of the piping element upon which the radial load is applied that is adjacent the weld to the weld midplane is at least equal to about one-half the thickness of the piping element upon which the load is applied. The amount of the radial load applied is sufficient to permanently reduce the outside diameter at the midplane of the section of the piping element in the range of about 0.2 to about 2.0 percent.